Papers
Plastic Pipes Conference Association # 2016 Berlin
Jan H. Sällström, Johan Sandström, Sven E. Sällberg
Flange joints connecting plastic pipes to valves are studied. The pipes have a reduced flange adaptor or a HP-flange adaptor. In the full scale experiments all flanges have a bolt circle diameter Ø725 mm. Four types of gaskets are used: an O-ring, a standard and a profiled gasket of EPDM with a steel core without and with an O-ring part, respectively, and also a planar gasket. In parallel, finite element analyses have been used for simulating the bolt tightening and relaxation of the flange joints investigated.
Water tightness of flange joints at valves has been investigated. Two flange adaptors of polyethylene have been used in the experimental and numerical studies. Four different gaskets have been studied: an integrated O-ring along with a reduced flange, a standard and a profiled rubber gasket with the steel core without and with the O-ring part, respecttively, and also a planar gasket. In the experiments, threads and other slip surfaces have been lubricated to achieve an even distribution of bolt forces and less friction losses.
Large variations in the bolt forces are measured. A simulation shows that despite the large variations, the sealing pressure in the circumferential direction is constant when a rubber gasket with the steel core is used.
Experiments have shown that for the profiled rubber gasket, it took less than 60 % of the recommended torque to achieve tightness. This applies also to the reduced flange with the integrated O-ring.
In all experiments the joints remained tight during the test period of more than a week. The simulations show that the tightness is preserved for 100 years for all the studied joints with the profiled rubber gasket. HP-flange remains tight for 100 years with all types of studied gaskets.
To obtain tight joints this study supports the use of profiled rubber gaskets with the steel core and the O-ring part or, alternatively, reduced flanges with integrated O-rings.
Advantages of using primarily the profiled rubber gasket are
- It will initially be tight at low bolt forces
- It seems to be less sensitive to varying tightening
- It has a self-sealing function, which provides a matching sealing pressure
- It is robust against displacements between flanges
Related papers
Author(s) : A. Marangoni
The quality of infrastructures is a key driver for maximizing the performance of the utilities networks and minimizing the environmental impacts associated with their operation. The water and sewer pipes are key network elements to guarantee a satisfactory service to the citizens. Their end-of-life management is an...
Author(s) : Li, Yanjun, Xiang, Aimin, Xu, HaiyunBeijing, Xie, Jianling, Ho, Kinman, Xu, HaiyunBeijing
It is necessary to evaluate the impact resistance of plastics pipes as they have the potential to be damaged by hitting or colliding during storage, transportation and installation. As a well-established test method, the Charpy impact strength of unnotched test pieces cut from thermoplastics pipes is determined...
Author(s) : A. Taraiya, P. Degenhart, M. Soliman, M. Boerakker, R. Handstanger, R. Kleppinger
Since the introduction of polyolefins for pressure pipes, continuous improvements have been made to meet ever-higher demands on their performance and to expand their application window beyond their original scope, mostly based on new resin formulations. Today, we also continue to push the limit to provide better...
Author(s) : Derek Muckle
A technical program has been undertaken to provide evidence on the suitability of polyethylene pipe and fitting systems for the distribution of hydrogen fuel gas. The underlying principle has been to evaluate material in the form of a pipe and to consider the performance of the pipe and of the welded jointing systems...
Author(s) : Donald Swen, Leanne Pichay, Nicholas Vallin, Alice Wu, Jim Johnston
In the rural commune of Ait Bayoud, Morocco, two of the most remote villages in the area, Ilguiloda and Izgouaren, live with water scarcity. To meet their water needs, women and children walk several kilometers to the nearest spring each day, often multiple times a day. Consequently, children cannot attend school...
Author(s) : Andreas Moerman, Flip van der Valk, Mirjam Blokker KWR, Tjakko Haaijer, Jan Vreeburg,
Drinking water companies with ageing networks are facing vast amounts of drinking water network reconstructions during the coming decades. This development coincides with the energy transition, which puts pressure on the available space underground. These external drivers give drinking water companies an opportunity...
Author(s) : Peter Hubbard, Linqing Luo, Andrew Yeskoo, Kenichi Soga, Krista (Moita) Araica, Gus Cicala, Marshall McLeod
Seismically active faults pose a risk to buried water pipelines that can be complicated to quantify. Fault type, slip rate, pipeline geometry, and soil conditions all factor into a complex soil-pipeline interaction. For critical pipelines that cross faults, high-density polyethylene (HDPE) has become an attractive...
Author(s) : Anders Andtbacka, Peter Sejersen
In the late nineties a study of the behavior of buried thermoplastics pipes was carried out. The project had input and participants from both the plastic pipe industry as well as from external organizations. Six external leading experts in the field of pipeline design, not necessarily plastics pipes design, have been...
Author(s) : Dominique GUEUGNAUT, Pascal AUSSANT, Romuald BOUAFFRE, Myriam BECHROURI
Concerns regarding the environment and sustainable development have revived interest in the reprocessing and re-use of polymer materials from manufactured objects that have reached the end of their operating life. Within this framework, formal professional agreements have been put in place at global level under the...
Author(s) : Paul J. Freudenthaler, Joerg Fischer, Mathias Eder, Reinhold W. Lang
For controlled water disinfection, typically chlorine is used and preliminary studies demonstrate its aging and crack growth acceleration effects on polyolefin pipe materials [1, 2]. Although the use of recycled plastics is not prohibited in some ISO standards for polyolefin piping systems [3–5], only small amounts...
Author(s) : Mike Troughton, Amir Khamsehnezhad, Changyi Yu
When butt fusion welding polyethylene (PE) pipes in the field, it is often specified that the pipes must undergo fusibility testing in all combinations of suppliers, diameters and thicknesses before being fused in production. This is a very onerous and expensive task, but must be carried out to ensure that the PE...
Author(s) : Shuhei Nishida, Shintaro Iwasaki, Hidefumi Yamanaka, Takahiro Kasatani
Polyethylene pipelines have been used for natural gas service applications for over 40 years in Japan. It is thought that they will continue to be used widely for many years. Therefore, it is important to confirm the conditions of the existing pipelines being used for the long term. In this study, polyethylene pipes...
Author(s) : Ernst van der Stok
For PE 100-RC, two tests are still under development for pipes: the point load test (PLT) and the accelerated notch pipe test (aNPT). The PLT was developed by a project group consisting of manufacturers and end users. The PLT determines the resistance to point loads as they can occur in practice. An earlier study...
Author(s) : S. Nestelberger, J. Cheng
The Point Load Test (PLT) [ 1, 2] was designed to simulate the SCG (slow crack growth) failure initiated by a rock pressing into the exterior wall of a polymer pipe. Today’s PE materials sustain long PLT testing times, due to its high SCG resistance design. Consequently, an accelerated “PLT+” with the support of...
Author(s) : Dr. Holger Brüning, Serge Hascoët, Yann Delanne, Didier Nozahic, Jawdat Mansour, José Santana
RTE operates, maintains and develops the French electricity network, including the High and very High Voltage cable lines. Their network is the largest in Europe and includes over 6400 km of underground HV links operated in 2018. The company is modernizing and developing its network by investing 1.5 billion euros per...
Author(s) : Greg Scoby, PE
This paper will detail the steps taken during adoption of HDPE for potable water systems improvements including material justification, creation of related specifications, investigation of available piping components, qualification of contractors and the construction/inspection of related systems. The City of...
Author(s) : Stephan Kneck, Henrik Iskov
It has become ever clearer that the resources of natural gas are an energy source, which will be less important in the future due to limitations in use of natural reserves. In order to prepare for the future the gas industry is looking at the alternative fuel gases, one such fuel gas is hydrogen. In order to prepare...
Author(s) : Christian Schalich
Plastic pipes for infrastructure and building applications are precisely specified with regards to wall thickness and diameter. Pipe manufacturers use different measuring methods in order to ensure the required dimensional accuracy and maintain a constant high quality. This paper introduces a measuring system based on...
Author(s) : Eng. Grigorios Vigellis, Eng. Mohamed Hageb
Continuous development and innovation in the production of plastic pipes made by high density polyethylene (HDPE) has enabled the industry to produce much larger diameter systems than ever believed possible. The enablers for production of such large plastic pipes are three main pillars: continuous innovation...
Author(s) : Jennifer Ravereau, Jose Teixeira Pinto, Malena Bernabeu, Jose Alacid, Jean-Philippe Le Goff, Frederic Mohier, Benjamin Rabaud
Drinking water network fittings such as valves are made of brass materials known to be robust over long periods. Due to the gradual inflation metallic raw material costs, composite plastic valves have grown in market share. Uncertainties remain, however, on their long-term reliability. The aim of this work is to...
Members of the Association
